- Old Ford Place
- Olson Place
- Outback Mobile Home Settlement
- Ozan
- Orchard Hills Mobile Home Park
- Old Weiss and French Place
- Old Banks Place
- Outlook
- Oliverville
- Old Hellgate Village Trailer Park
- Old Town
- Old Whitcomb Place
- Orinoco
- Oilmont
- Olive
- Ollie
- Olney
- Opportunity
- Oswego
- Otter
- Ohio Camp
- Old Agency
- Opheim
- Orchard Homes
- Ovando